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  • Check if an object is facing another based on angles

    - by Isaiah
    I already have something that calculates the bearing angle to get one object to face another. You give it the positions and it returns the angle to get one to face the other. Now I need to figure out how tell if on object is facing toward another object within a specified field and I can't find any information about how to do this. The objects are obj1 and obj2. Their angles are at obj1.angle and obj2.angle. Their vectors are at obj1.pos and obj2.pos. It's in the format [x,y]. The angle to have one face directly at another is found with direction(obj1.pos,obj2.pos). I want to set the function up like this: isfacing(obj1,obj2,area){...} and return true/false depending if it's in the specified field area to the angle to directly see it. I've got a base like this: var isfacing = function (obj1,obj2,area){ var toface = direction(obj1.pos,obj2.pos); if(toface+area >= obj1.angle && ob1.angle >= toface-area){ return true; } return false; } But my problem is that the angles are in 360 degrees, never above 360 and never below 0. How can I account for that in this? If the first object's angle is say at 0 and say I subtract a field area of 20 or so. It'll check if it's less than -20! If I fix the -20 it becomes 340 but x < 340 isn't what I want, I'd have to x 340 in that case. Is there someone out there with more sleep than I that can help a new dev pulling an all-nighter just to get enemies to know if they're attacking in the right direction? I hope I'm making this harder than it seems. I'd just make them always face the main char if the producer didn't want attacks from behind to work while blocking. In which case I'll need the function above anyways. I've tried to give as much info as I can think would help. Also this is in 2d.

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  • Is that true that .Net will be dumped by Microsoft in Windows 8? [closed]

    - by Dee Jay
    Possible Duplicate: What does Windows 8 mean for the future of .NET? Ok, I read this question and someone pointed that C# will be sidelined in next version of windows. There is a link in that question pointed at another link, i.e. this one: Dumping .NET - Microsoft's Madness Is that true that .Net will be dumped by Microsoft in Windows 8? Someone with insider information please share with us your opinions. I'm deeply worried about this.

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  • Refactoring and Open / Closed principle

    - by Giorgio
    I have recently being reading a web site about clean code development (I do not put a link here because it is not in English). One of the principles advertised by this site is the Open Closed Principle: each software component should be open for extension and closed for modification. E.g., when we have implemented and tested a class, we should only modify it to fix bugs or to add new functionality (e.g. new methods that do not influence the existing ones). The existing functionality and implementation should not be changed. I normally apply this principle by defining an interface I and a corresponding implementation class A. When class A has become stable (implemented and tested), I normally do not modify it too much (possibly, not at all), i.e. If new requirements arrive (e.g. performance, or a totally new implementation of the interface) that require big changes to the code, I write a new implementation B, and keep using A as long as B is not mature. When B is mature, all that is needed is to change how I is instantiated. If the new requirements suggest a change to the interface as well, I define a new interface I' and a new implementation A'. So I, A are frozen and remain the implementation for the production system as long as I' and A' are not stable enough to replace them. So, in view of these observation, I was a bit surprised that the web page then suggested the use of complex refactorings, "... because it is not possible to write code directly in its final form." Isn't there a contradiction / conflict between enforcing the Open / Closed Principle and suggesting the use of complex refactorings as a best practice? Or the idea here is that one can use complex refactorings during the development of a class A, but when that class has been tested successfully it should be frozen?

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  • Why do memory-managed languages retain the `new` keyword?

    - by Channel72
    The new keyword in languages like Java, Javascript, and C# creates a new instance of a class. This syntax seems to have been inherited from C++, where new is used specifically to allocate a new instance of a class on the heap, and return a pointer to the new instance. In C++, this is not the only way to construct an object. You can also construct an object on the stack, without using new - and in fact, this way of constructing objects is much more common in C++. So, coming from a C++ background, the new keyword in languages like Java, Javascript, and C# seemed natural and obvious to me. Then I started to learn Python, which doesn't have the new keyword. In Python, an instance is constructed simply by calling the constructor, like: f = Foo() At first, this seemed a bit off to me, until it occurred to me that there's no reason for Python to have new, because everything is an object so there's no need to disambiguate between various constructor syntaxes. But then I thought - what's really the point of new in Java? Why should we say Object o = new Object();? Why not just Object o = Object();? In C++ there's definitely a need for new, since we need to distinguish between allocating on the heap and allocating on the stack, but in Java all objects are constructed on the heap, so why even have the new keyword? The same question could be asked for Javascript. In C#, which I'm much less familiar with, I think new may have some purpose in terms of distinguishing between object types and value types, but I'm not sure. Regardless, it seems to me that many languages which came after C++ simply "inherited" the new keyword - without really needing it. It's almost like a vestigial keyword. We don't seem to need it for any reason, and yet it's there. Question: Am I correct about this? Or is there some compelling reason that new needs to be in C++-inspired memory-managed languages like Java, Javascript and C#?

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  • How much time takes to a new language like D to become popular? [closed]

    - by Adrián Pérez
    I was reading about new languages for me to learn and I find very good comments about D, like it's the new C or what C++ should have been. Knowing that many people say wonders about the language, I'm wondering how much time usually takes to a language to become popular. This is, having libraries ported or written natively for this language and being used in serious software development. I have read about the history of Java, and Python to figure it out, but may be they are too high level complexity to say their development could take the same time as will take for D.

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  • Is there a point to writing in C or C++ instead of C# without knowing specifically what would make a program faster?

    - by user828584
    I wrote a small library in Python for handling the xbox 360's STFS files to be used on my web applications. I would like to rewrite it for use in the many desktop programs people are writing for 360 game modding, but I'm not quite if I should continue using C# or delve into C++ or even C. STFS is an in-file file system used by the xbox 360 and the job of the library would be extracting/injecting files, which could take noticeable amounts of time to do. What I know in C# comes from internet tutorials and resources, as would anything I learn about C++, so what I'm asking is if it's better to bring myself to a slightly lower-level language without knowing beforehand the features of the language that increase performance, or continue assuming that compiler optimizations and that my lack of experience will mean that the language I choose won't matter.

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  • How to deal with tautology in comments?

    - by Tamás Szelei
    Sometimes I find myself in situations when the part of code that I am writing is (or seems to be) so self-evident that its name would be basically repeated as a comment: class Example { /// <summary> /// The location of the update. /// </summary> public Uri UpdateLocation { get; set; }; } (C# example, but please refer to the question as language-agnostic). A comment like that is useless; what am I doing wrong? Is it the choice of the name that is wrong? How could I comment parts like this better? Should I just skip the comment for things like this?

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  • How do I print values of an array in Three Rows?

    - by Ramkumar
    I need this output.. 1 3 5 2 4 6 I want to use array function like array(1,2,3,4,5,6). If I edit this array like array(1,2,3), it means the output need to show like 1 2 3 The concept is maximum 3 column only. If we give array(1,2,3,4,5), it means the output should be 1 3 5 2 4 Suppose we will give array(1,2,3,4,5,6,7,8,9), then it means output is 1 4 7 2 5 8 3 6 9 that is, maximum 3 column only. Depends upon the the given input, the rows will be created with 3 columns. Is this possible with PHP? I am doing small Research & Development in array functions. I think this is possible. Will you help me? For more info: * input: array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15) * output: 1 6 11 2 7 12 3 8 13 4 9 14 5 10 15

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  • Which web site gives the most accurate indication of a programmer's capabilities?

    - by Jerry Coffin
    If you were hiring programmers, and could choose between one of (say) the top 100 coders on topcoder.com, or one of the top 100 on stackoverflow.com, which would you choose? At least to me, it would appear that topcoder.com gives a more objective evaluation of pure ability to solve problems and write code. At the same time, despite obvious technical capabilities, this person may lack any hint of social skills -- he may be purely a "lone coder", with little or no ability to help/work with others, may lack mentoring ability to help transfer his technical skills to others, etc. On the other hand, stackoverflow.com would at least appear to give a much better indication of peers' opinion of the coder in question, and the degree to which his presence and useful and helpful to others on the "team". At the same time, the scoring system is such that somebody who just throws up a lot of mediocre (or even poor answers) will almost inevitably accumulate a positive total of "reputation" points -- a single up-vote (perhaps just out of courtesy) will counteract the effects of no fewer than 5 down-votes, and others are discouraged (to some degree) from down-voting because they have to sacrifice their own reputation points to do so. At the same time, somebody who makes little or no technical contribution seems unlikely to accumulate a reputation that lands them (even close to) the top of the heap, so to speak. So, which provides a more useful indication of the degree to which this particular coder is likely to be useful to your organization? If you could choose between them, which set of coders would you rather have working on your team?

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  • Generalise variable usage inside code

    - by Shirish11
    I would like to know if it is a good practice to generalize variables (use single variable to store all the values). Consider simple example Strings querycre,queryins,queryup,querydel; querycre = 'Create table XYZ ...'; execute querycre ; queryins = 'Insert into XYZ ...'; execute queryins ; queryup = 'Update XYZ set ...'; execute queryup; querydel = 'Delete from XYZ ...'; execute querydel ; and Strings query; query= 'Create table XYZ ... '; execute query ; query= 'Insert into XYZ ...'; execute query ; query= 'Update XYZ set ...'; execute query ; query= 'Delete from XYZ ...'; execute query ; In first case I use 4 strings each storing data to perform the actions mentioned in their suffixes. In second case just 1 variable to store all kinds the data. Having different variables makes it easier for someone else to read and understand it better. But having too many of them makes it difficult to manage. Also does having too many variables hamper my performance?

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  • undefined control sequence in a NOWEB document

    - by Jean Baldraque
    I'm writing a TeX-noweb document. I compile it with noweave -tex -filter "elide comment:*" texcode.nw > documentation.tex but when I try to compile the resulting file with xetex -halt-on-error documentation.tex I obtain the following error message ! Undefined control sequence. <argument> ...on}\endmoddef \nwstartdeflinemarkup \nwenddeflinemarkup It seems that \nwenddeflinemarkup is not recognized. If i delete from the document all the sequences \nwstartdeflinemarkup\nwenddeflinemarkup the document compile without exceptions. What can be the problem?

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  • What features would you like to have in PHP? [closed]

    - by StasM
    Since it's the holiday season now and everybody's making wishes, I wonder - which language features you would wish PHP would have added? I am interested in some practical suggestions/wishes for the language. By practical I mean: Something that can be practically done (not: "I wish PHP would guess what my code means and fix bugs for me" or "I wish any code would execute under 5ms") Something that doesn't require changing PHP into another language (not: "I wish they'd drop $ signs and use space instead of braces" or "I wish PHP were compiled, statically typed and had # in it's name") Something that would not require breaking all the existing code (not: "Let's rename 500 functions and change parameter order for them") Something that does change the language or some interesting aspect of it (not: "I wish there was extension to support for XYZ protocol" or "I wish bug #12345 were finally fixed") Something that is more than a rant (not: "I wish PHP wouldn't suck so badly") Anybody has any good wishes? Mod edit: Stanislav Malyshev is a core PHP developer.

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  • What to use C++ for?

    - by futlib
    I really love C++. However, I'm struggling to find good uses for it lately. It is still the language to use if you're building huge systems with huge performance requirements. Like backend/infrastructure code at Google and Facebook, or high-end games. But I don't get to do stuff like that. It's also a good choice for code that runs close to the hardware. I'd like to do more low-level stuff, but it isn't part of my job, and I can't think of useful private projects that would involve that. Traditionally, C++ was also a good choice for rich client applications, but those are mostly written in C# and Obj-C lately - and aren't really that important anymore, with everything being a web app. Or a mobile app, which are mostly written in Obj-C and Java. And of course, web-based desktop and mobile apps are quite prominent, too. At my job, I work mostly on web applications, using Java, JavaScript and Groovy. Java is a good/popular choice for non-Google-scale backends, Groovy (or Python, or Ruby or Node.js) is pretty good for the server-side of web apps and JavaScript is the only real choice for the client-side. Even the little games I'm writing in my spare time are lately mostly written in JavaScript, so they can run in the browser. So what would you suggest I could use C++ for? I'm aware that this question is very similar. However, I don't want to learn C++, I was a professional C++ programmer for years. I want to keep doing it and find good new use cases for it. I know that I can use C++ for web apps/games. I could even compile C++ to JavaScript with Emscripten. However, it doesn't seem like a good idea. I'm looking for something C++ is really good at to stay competent in the language. If your answer is: Just give up and forget C++, you'll probably never need it again, so be it.

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  • Is the copy/paste approach professionally viable when working with the Google Maps API?

    - by Ian Campbell
    I find that I understand much of the Javascript concepts used in the Google Maps API code, but then again there is quite a bit that is way over my head in syntax. For example, the geocoder syntax seems to be of Ajax form, though I don't understand what is happening under the hood (especially with lines like results[0].geometry.location). I am able to modify the body of if (status == google.maps.GeocoderStatus.OK) for different purposes though. So, being that I am able to take various code from the Developer's Guide and rework it to an extent for my own purposes, all the while not fully understanding what Google Maps is actually doing, does this make me a copy-paste programmer? Is this a bad practice, or is this professionally viable? I am, of course, interested in learning as much as I can, but what if time-constraints outweigh the learning process?

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  • graphical interface when using assembly language

    - by Hellbent
    Im looking to use assembly language to make a great game, not just an average game but a really great game. I want to learn a framework to use in assembly. I know thats not possible without learning the framework in c first. So im thinking of learning sdl in c and then learn, teach myself, how to interpret the program and run it as assembly language code which shouldnt be that hard. Then i will have a window and some graphics routines to display the game while using assembly to code everything in. I need to spend some time learning sdl and then some more time learning how to code all those statements using assembly while calling c functions and knowing what registers returned calls use and what they leave etc. My question is , Is this a good way to go or is there something better to get a graphical window display using assembly language? Regards HellBent

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  • How can I optimize my development machines files/dirs?

    - by LuxuryMode
    Like any programmer, I've got a lot of stuff on my machine. Some of that stuff is projects of my own, some are projects I'm working on for my employer, others are open-source tools and projects, etc. Currently, I have my files organized as follows: /Code --/development (things I'm sort of hacking on plus maybe libraries used in other projects) --/scala (organized by language...why? I don't know!) --/android --/ruby --/employer_name -- /mobile --/android --/ios --/open-source (basically my forks that I'm pushing commits back upstream from) --/some-awesome-oss-project --/another-awesome-one --/tools random IDE settings sprinkled in here plus some other apps As you can see, things are kind of a mess here. How can I keep things organized in some sort of coherent fashion?

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  • Stuff you learned in school, that you have never used again?

    - by Mercfh
    Obviously we learn plenty of things in our University/College/Whatever that probably don't apply to everyday use, but is there anything that stands out particularly? Maybe something that was concentrated ALOT on? For me it was def. 2 things: OO Concepts and Pointers I still use OO, but not nearly to the amount people made it out to be, i can see where it'd be useful but in my line of work we don't have huge amounts of classes, maybe a couple at most. And there certainly isn't much OO reuse (i finally figured out what that means lol) Pointers are another thing, again I can see where they'd be useful...however I barely barely ever touch them, nor do the others I work with. I guess language choice has alot to do with that but still. What about you guys? edit: For those who are asking I work for a Large Printer company, and most of the Applications we work on are Java+XML and Actionscript for "Printer Apps". But we are moving towards other languages (think like webkits and stuff). So the Code amounts per parts are quite small. I never say OO wasn't useful I just said I personally havent seen it used in my workplace much.

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  • Should I modify an entity with many parameters or with the entity itself?

    - by Saeed Neamati
    We have a SOA-based system. The service methods are like: UpdateEntity(Entity entity) For small entities, it's all fine. However, when entities get bigger and bigger, to update one property we should follow this pattern in UI: Get parameters from UI (user) Create an instance of the Entity, using those parameters Get the entity from service Write code to fill the unchanged properties Give the result entity to the service Another option that I've experienced in previous experiences is to create semantic update methods for each update scenario. In other words instead of having one global all-encompasing update method, we had many ad-hoc parametric methods. For example, for the User entity, instead of having UpdateUser (User user) method, we had these methods: ChangeUserPassword(int userId, string newPassword) AddEmailToUserAccount(int userId, string email) ChangeProfilePicture(int userId, Image image) ... Now, I don't know which method is truly better, and for each approach, we encounter problems. I mean, I'm going to design the infrastructure for a new system, and I don't have enough reasons to pick any of these approaches. I couldn't find good resources on the Internet, because of the lack of keywords I could provide. What approach is better? What pitfalls each has? What benefits can we get from each one?

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  • Where can I find game postmortems with a programmer perspective [on hold]

    - by Ken
    There are a number of interesting game post-mortems in places like GDC vault or gamastura.com. The post-mortems are generally give with a CEO/manager perspective or a designer perspective, or, more often a combination of both e.g DOOM postmortem But I have not been able to find many post-mortems which are primarily from the programmers perspective. I'm looking for discussions and rational for technical choices and tradeoffs and how technical problems were overcome. The motivation here is to learn what kind of problems real game programmers encounter and how they go about solving them. A perfect example of what I'm looking for is Renaud Bédard's excellent GDC talk on the development of Fez, "Cubes all the way down". Where can I find more like that?

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  • Maximum Length Of IP Address: 15 (IPv4) & 39(IPv6)

    - by Gopinath
    Problem You are designing a database table for a web application that requires to store IP address of users who visits the site. The IP address is required to be stored a character data in the table. To define size of the character column you need to know maximum length of IP address. So, what is the maximum length of an IP address? Solution The IPv4 version of IP address is in the following format 255.255.255.255 To store IPv4 address we require 15 characters. The IPv6 version of IP address is grouped into sets of 4 hex digits separated by colons, like the below 2001:0db8:85a3:0000:0000:8a2e:0370:7334 To store IPv6 address you require a 39 characters long column. Conclusion As IPv4 and IPv6 are the commonly use protocols, you better define a column with 39 characters length so that both the format address are saved in to the table without any issues. This article titled,Maximum Length Of IP Address: 15 (IPv4) & 39(IPv6), was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • What is the meaning of 'high cohesion'?

    - by Max
    I am a student who recently joined a software development company as an intern. Back at the university, one of my professors used to say that we have to strive to achieve "Low coupling and high cohesion". I understand the meaning of low coupling. It means to keep the code of separate components separately, so that a change in one place does not break the code in another. But what is meant by high cohesion. If it means integrating the various pieces of the same component well with each other, I dont understand how that becomes advantageous. What is meant by high cohesion? Can an example be explained to understand its benefits?

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  • Motivation and use of move constructors in C++

    - by Giorgio
    I recently have been reading about move constructors in C++ (see e.g. here) and I am trying to understand how they work and when I should use them. As far as I understand, a move constructor is used to alleviate the performance problems caused by copying large objects. The wikipedia page says: "A chronic performance problem with C++03 is the costly and unnecessary deep copies that can happen implicitly when objects are passed by value." I normally address such situations by passing the objects by reference, or by using smart pointers (e.g. boost::shared_ptr) to pass around the object (the smart pointers get copied instead of the object). What are the situations in which the above two techniques are not sufficient and using a move constructor is more convenient?

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  • Why to say, my function is of IFly type rather than saying it's Airplane type

    - by Vishwas Gagrani
    Say, I have two classes: Airplane and Bird, both of them fly. Both implement the interface IFly. IFly declares a function StartFlying(). Thus both Airplane and Bird have to define the function, and use it as per their requirement. Now when I make a manual for class reference, what should I write for the function StartFlying? 1) StartFlying is a function of type IFly . 2) StartFlying is a function of type Airplane 3) StartFlying is a function of type Bird. My opinion is 2 and 3 are more informative. But what i see is that class references use the 1st one. They say what interface the function is declared in. Problem is, I really don't get any usable information from knowing StartFlying is IFly type. However, knowing that StartFlying is a function inside Airplane and Bird, is more informative, as I can decide which instance (Airplane or Bird ) to use. Any lights on this: how saying StartFlying is a function of type IFly, can help a programmer understanding how to use the function?

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  • "Opportunity" to take over maintenance of a small internal website. What should I do?

    - by Dan
    I have been offered an "opportunity" to take over maintenance of a small internal website run by my group that provides information about schedules and photos of events the groups done. My manager sent me the link to the site and checked it out. The site looked clean and neat but loaded in ~5 seconds. I thought this was a little long considering the site really didn't contain a lot of content. This prompted me to take a look under the hood at the pages source code. To my horror it'd been totally hacked together using nested tables! I'm new so I really can't say no to this "opportunity" so what should I do with it? Every fiber of my being feels that the only correct thing to do is over hall the site using CSS, Div's, Span's and any other appropriate tags that a sane/good web developer would used to begin with instead of depending on the render incentive magic of tables. But I'd like to ask programmers with more experienced then me, who have been in this situation. What should I do? Is my only realistic option to leave the horror as is and only adjusting the content as requested? I'm really torn between good development and the corporate reality I'm part of. Is there some kind of middle ground where things can be made better even if they're not perfect? Thanks ahead of time.

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  • "Imprinting" as a language feature?

    - by MKO
    Idea I had this idea for a language feature that I think would be useful, does anyone know of a language that implements something like this? The idea is that besides inheritance a class can also use something called "imprinting" (for lack of better term). A class can imprint one or several (non-abstract) classes. When a class imprints another class it gets all it's properties and all it's methods. It's like the class storing an instance of the imprinted class and redirecting it's methods/properties to it. A class that imprints another class therefore by definition also implements all it's interfaces and it's abstract class. So what's the point? Well, inheritance and polymorphism is hard to get right. Often composition gives far more flexibility. Multiple inheritance offers a slew of different problems without much benefits (IMO). I often write adapter classes (in C#) by implementing some interface and passing along the actual methods/properties to an encapsulated object. The downside to that approach is that if the interface changes the class breaks. You also you have to put in a lot of code that does nothing but pass things along to the encapsulated object. A classic example is that you have some class that implements IEnumerable or IList and contains an internal class it uses. With this technique things would be much easier Example (c#) [imprint List<Person> as peopleList] public class People : PersonBase { public void SomeMethod() { DoSomething(this.Count); //Count is from List } } //Now People can be treated as an List<Person> People people = new People(); foreach(Person person in people) { ... } peopleList is an alias/variablename (of your choice)used internally to alias the instance but can be skipped if not needed. One thing that's useful is to override an imprinted method, that could be achieved with the ordinary override syntax public override void Add(Person person) { DoSomething(); personList.Add(person); } note that the above is functional equivalent (and could be rewritten by the compiler) to: public class People : PersonBase , IList<Person> { private List<Person> personList = new List<Person>(); public override void Add(object obj) { this.personList.Add(obj) } public override int IndexOf(object obj) { return personList.IndexOf(obj) } //etc etc for each signature in the interface } only if IList changes your class will break. IList won't change but an interface that you, someone in your team, or a thirdparty has designed might just change. Also this saves you writing a whole lot of code for some interfaces/abstract classes. Caveats There's a couple of gotchas. First we, syntax must be added to call the imprinted classes's constructors from the imprinting class constructor. Also, what happends if a class imprints two classes which have the same method? In that case the compiler would detect it and force the class to define an override of that method (where you could chose if you wanted to call either imprinted class or both) So what do you think, would it be useful, any caveats? It seems it would be pretty straightforward to implement something like that in the C# language but I might be missing something :) Sidenote - Why is this different from multiple inheritance Ok, so some people have asked about this. Why is this different from multiple inheritance and why not multiple inheritance. In C# methods are either virtual or not. Say that we have ClassB who inherits from ClassA. ClassA has the methods MethodA and MethodB. ClassB overrides MethodA but not MethodB. Now say that MethodB has a call to MethodA. if MethodA is virtual it will call the implementation that ClassB has, if not it will use the base class, ClassA's MethodA and you'll end up wondering why your class doesn't work as it should. By the terminology sofar you might already confused. So what happens if ClassB inherits both from ClassA and another ClassC. I bet both programmers and compilers will be scratching their heads. The benefit of this approach IMO is that the imprinting classes are totally encapsulated and need not be designed with multiple inheritance in mind. You can basically imprint anything.

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